Many thanks for this very helpful Howto! Works perfectly!
Question: The common name for the resulting certificate seems to be "vgapps.de", not "*.vgapps.de" (no asterisk). This does not seem to be a problem for my client (Firefox), but I see, that other wildcard certificates (e.g. by GeoTrust) have the asterisk in the common name. Why is it different and can this difference lead to problems?